Consistent use of antiretroviral medications by adults living with HIV can suppress plasma HIV-1 RNA (viral load) to undetectable levels and thereby improve survival rates and quality of life, and reduce HIV-related infections, health care costs, and transmission of HIV. Despite the potential benefits of antiretroviral therapy, adults living wih HIV have not been reliably engaged in HIV care or sustained on antiretroviral medications. Few interventions have been shown effective in increasing adherence and suppressing viral loads to undetectable levels, and no treatments have produced long-term effects that sustain after the intervention is discontinued. Interventions that provide incentives to patients when they meet required therapeutic goals have been demonstrated extraordinarily effective in promoting therapeutic behavior change in diverse populations and they have shown promise in promoting adherence to antiretroviral medications and suppression of viral loads. However, only limited evaluations of these interventions have been conducted to promote adherence to antiretroviral medications and suppress viral loads, those evaluations have not employed optimal parameters of incentive interventions, and they have not produced levels of viral load suppression that are needed clinically. We propose to evaluate a novel incentive intervention to promote suppression of viral load in people living with HIV that will employ empirically-based parameters that have been proven critical to the effectiveness of incentive interventions. Participants (N = 200) from two medical clinics that serve adults living with HIV in Baltimore will be randomly assigned to an Incentive or a Usual Care Control group. Incentive group participants will receive incentives for maintaining suppressed and undetectable viral loads. The incentive program will employ high magnitude incentives, provide incentives for decreases in viral load early in treatment before a patient s viral load has reached undetectable levels, arrange frequent incentives early in treatment and reduce the frequency of incentives as participants achieve progressively longer periods of viral load suppression, arrange a schedule of escalating incentives for sustained suppression of viral load, and the intervention will be maintained for two years. Usual Care Control participants will only receive the standard HIV medical care offered in their clinic. Assessments will be conducted every 3 months throughout the two years of treatment and every 6 months throughout the year following treatment. The primary outcome measure will be the percentage of participants that have undetectable viral loads at the 3-month assessments conducted throughout the 2-year intervention period. Secondary measures will include adherence to HIV care and post- treatment outcomes. We will also assess moderators and mediators of the effects of the incentives on the suppression of viral load, and conduct cost-effectiveness and cost-benefit analyses. If the incentive intervention maintains suppressed viral load and is economically sound, it could be used to improve the health of adults living with HIV, reduce health care costs, and reduce HIV transmission in the community.